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Date: Fri, 7 Jan 2011 17:27:27 +0100
From: Frederic Weisbecker <fweisbec@gmail.com>
To: Jan Beulich <JBeulich@novell.com>
Cc: "H. Peter Anvin" <a.p.zijlstra@chello.nl>, Ingo Molnar <mingo@elte.hu>,
        Stephane Eranian <eranian@google.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Arnaldo Carvalho de Melo <acme@redhat.com>,
        Soeren Sandmann Pedersen <sandmann@redhat.com>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH 1/2] x86: Fix rbp saving in pt_regs on irq entry
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On Fri, Jan 07, 2011 at 04:13:58PM +0000, Jan Beulich wrote:
> >>> On 07.01.11 at 17:05, Frederic Weisbecker <fweisbec@gmail.com> wrote:
> > Once I'll have perf callchain based on CFI ready, we'll perhaps find some 
> > issues
> > there. Although I guess there are already tools that can make use of that.
> 
> Is this to read that you're planning to do a re-spin of the CFI
> unwinding code (which I'm not allowed to submit another time,
> but which we've been using for years in SuSE distros) then?

An in-kernel CFI unwinder?

No the intended CFI unwinding that I'm working on for perf is made
on post-processing, on top of partial stack and regs snapshots.

The true unwinding is computed in userspace.